Instrument for indicating angular motion



C. H. COLVIN INSTRUMENTv FOR INDICATING ANGULAR MOTION Filed July 5. 1919 l l 2 Sheets-Sheet l @A TTORNEY l Dec. 14`, 1926.

c. H.l coLvlN INSTRUMENO. FOR INDIOATING ANGULAR MOTION 2 Sheets-'Sheet 2 .Filed July 5, 1919 T TORNE Y Patented Dee. 14, 1926.

11151111121)4 STATES 1,610,930 Pn'rnrirl OFFICE.

CHARIES HI.y COLVIN, OF BROOKLYN, NEW YORK.

INSTRUMENT FOR INDICATING ANGULAR MOTION.

i Application led July 5,

. navigated by night or through fogs by `providing the pilot With a simple instrument which he may watch through the flight and seldom be put to the necessity of observing land marks. f

It is 'also an object and particularly desir able to have more than one means incorporated in a single navigating instrument to vary the sensitivity characteristics thereof, so that one means may be used to alter the characteristics of the instrument to ada-pt it ,to the particular type of craft, as for example a slow or fast machine; and another adjusting means to alter the characteristics of the device to adapt it or suit it to particular conditions of flight such as smooth oriroug'h air, or the varymg tempel-mental wishes of the pilot.

The essential features of my invention arel the embodiment of a simple air driven gyroscopic element arranged to produce a sensit-ive indication thru an indicator. and simple means to vary the indicating characteristics of the gyroscope so the sensitivity of the deviceA may be readily adjusted by the pilot to suit particular conditions at'the tune of flight. The sensitivity adjusting feature is one of much consequence, for without it a manufacturer to be successful with introduction of the invention on the market, would necessarily have to build many different models thereby increasing the cost and lhandicapping the facilityand ease with which the instrument is now being used.

While I am aware that air driven gyroscopes are old, and gyro Compasses' and artificial horizon instruments Aare likewise old, and furthermore gyroscopes are used to facilitate the navigation `of vessels; yet it is new to produce a. small. compact, light weight instrument embodying the aforesaid features, and devoid of all electrical apparatus, to make an instrument specially fitted 1919. serial No. 308,861.

for aerial use -Where older gyro` instruments could not readily be used.

Figure 1 is a View in section, through the center of the instrument at right angles to the axis about which angular motion is'to be indicated, or upon the line 1-1 of Figure 3.

Figure 2 is a fragmentary view, partly in sectlon, through that part of Figure 1 indicated by the line-2,2.

Figure 3 is a sectional view on `the line Figure 4 is a View of the face of the instrument, when no angular motion is indicated. y

Figure`5 is a View of an indicating element removed from the casing of the instrument.

` igure 6 shows the face of the instrument as it appears inindicating a turn.

Figure? shows aviewV ofthe face iwhen the instrument is indicating a tu'rn opposite in direction to that of Figure 6 and at a`v slower rate of turn.

, Referring now more particularly to the drawings, wherein the same parts throughout the several views are designated by the same reference characters, the numeral l points out a substantially air-tight casing inWhich the lnstrument parts are contained. A pin or shaft 2 is fixed within one end of the casing 1. Journaled upon the pin 2 is one end of a frame. 3, the other end of which is reduced 'in size to form a shaft 4, which has attached to its extremity an indicator disc 5. A bearing plate or spider frame 6 is secured 1n the casing 1 and journals the shaft 4. The frame 3 is therefore rotatable about the jour nals on the pin 2 and the shaft 4. rlhe frame 3 has secured within it two pintle shafts 37 on which. the wheel 7 is rotatably supported. This wheel or rotor is notched on the periphery as shown at 34.

The'face of the instrument' is .sealed with a glass plate 8 held against the rubber gasket 9 by theV ring 10. The plate 8 is rendered opaque lby painting or other more approA prlate means, except for two view `openings 11 and 127 through which the indicator is observed.

A valve box 13 is secured in the casing 1, through which air may be admitted to the instrument. The valve 14 may be adjusted relatively to the box 13 to regulate or stop the flow of air. Another valve box 15 is sethrough the tube 16. The valve 17 may be' adjusted relatively to the air passage thru the box to regulate or stop the flow of air; and it is an advantage to use this valve during flight'to adjust the sensitivity of the inmatic'conditions existing at the time.

Referring particularly to Figure 2, the pin 2 is bored out so that, in addition to suporting the frame 3 as previously described, 1t contains a passage for admitting air to the instrument through the jet 18. This jet 18 is secured in the pin 2 by a set-screw or other means so that it may be -adjusted relatively to the wheel 7. -The valve 19 is threaded within the hollow pin 2 so that it may be moved relatively to the pin to regulate or stop the air flow through the jet 18.

An additional jet 20 may be employed in some types of instruments and is mounted in the case so that its inner end lies adjacent to the notches of the wheel for directing a stream of air against the wheel in opposition tothe turning moment so that the speed of the wheel may be regulated. An intake regulating valve 20e is employed to control the amount of air directed through the jet 20.

Referring again to Figure l, 2l designatesl a flexible tube or conduit through which air must pass to reach the passage in the hollow pin 2 and the jet 18. This tube may ,haveits other end, which is not shown, distantly located in respect to the instrument casing for the purpose of plbtaining a supply of lsuitable air, for example warm air, for running the gyroscopic wheel.

Referring now particularly to Figure 3, a ring 22 encircles the shaft 4 and is secured to the frame 3 so that it may be adjusted relatively to the frame. This ring 22 has an ear 23 to which is attached one end of a spring 24, and the other end of this spring 24 is secured to a screw 25. By means of a nut 26 or by other more appropriate means, the tension of the spring 24 may be adjusted to vary the centralizing effort of the spring onr the gyroscopic element 3-7. jThis Ispring tends to hold the frame 3 in a normal position, and stops 36 are provided to limit ,the angular movement of the frame /3, by preventing further rotation of the frame about its axis when the frame strikes one of said stops. It is particularly practical to use this spring to adjust the instrument so as to adapt it say, to a slow or fast craft, or

stable or unstable craft.

A in 27 is attached to the shaft 4, and hasvplvotally fitted to its upper end the link 28, the other end of which is pivot-ally attac-hed to the-piston rod 29. carrying a piston 30. This piston is reciprocatively confined in the cylinder 31. AIn the end of the cylinder 3l is .built af valve box. 32 connecting to the casing through the passage 33. A valve 34 is movable relatively to the air passage in the box 32 for regulating or stop ping the flow of air through the passage 33.' j Referring now to Figure 5, the indicator disc 5 is shown in a preferred form. The

n color portions or sectors 5a are of a color strument to suit the flight conditions or cli-v contrasting with that of the rest of the indicator disc. A preferred color combination is white or radium luminous material for parent view openings 11 and 12 therefore exposeo-nly the black surface'of the indicator 5. The opaque part of the glass plate 8 is preferably of the same color as the background Aof the indicator disc 5, which has been assumed to be black for the purpose of this description, and therefore the entire surface of the face of the instrument appears to be black.

In Figure 6, the instrument is shown with the indicator disc 5 rotated to give an indication of angular motion. The face of the instrument now appears as a black surface with one white sector indicating a, turn, which has caused the gyroscopic element -comprising the wheels and frame to work the indicator.

Proceeding now to a description of the functioning of the instrument, assume that the valve 14 and the jet 20 are closed and the valves 17 and 19 are open and that suction has been appliedto the tube 16 for a time sufficient to properly evacuate or rarefy the air in the casing. The only place where air may enter the case is through the jet 18. and air passing through this jet impinges on the vnotches 34 -cut in the periphery of the` wheel 7, causing the wheel to rotate at high speed. y

A wheel rotating at high speed vhas a Sli valuable characteristic which is employed in this instrument. If a revolving Wheel be turned about an axis at right angles to its axis of rotation, it will react by turning about an axis at right angles both to its axis of rotation and to the axis about which it has been turned. This performance of the wheel and movable frame is the result'l of gyroscopic force developed by the spinning-wheel which force causes the gyro element to move about the axis of the journals 2 and 4.A

Now suppose the entlre instrument to be rotated to simulate the turning motionv of an airplane. This angular motion will be,

about an axis perpendicular'to the plane of the drawing, as indicated by the arrows 35, and this angular motion tends to cause the -locking the jet in any position.

- and its regulating means..

` intereso rotating Wheel to move its supporting iframe frame is restrained by the spring 2t and the stops 36. A turning movement oiB the casing 1 or of the vehicle on which the instrument is mounted as shown by the arrows Sois therefore indicated on the 'face ot the instrument as shown in Figure 6. A turn of the vehicle in the oppositedirection would conversely be. indicated by the appearance of a White sector ofthe indicator on the opposite'side of the face of the instrument as in Figure 7.

ln certain uses of an indicator of angular motion it is desirable vthat the amount ont movement of the indicating means shall hey in certain relation to the `speed of angular motion, and it isalso desirable to have that relation easily alterable according to the pleasure of the user' of the instrument, for example according to the desire of an aviator navigating a flying machine.

rlhere are two principal factors upon which the relation between the rate of angu lar motion and the amount of indication depend. These are the'rotative speed of the Wheel and the strength of the spring 24.

ing it hy means ci screws in the position desired.

llt im cases disadvantageous to taire air nirectly into the case irorn the out side. lin vthis may he because of dampness Water the air near the in strurnent..` llt is also desirable to ohtain air from a remote ,source to secure air et a more suitable directly outside the caseo For this purpose the ,pipe 2l is used. This .may yhe a tieniiole conduit or solid tube ot such tengan as may he required to secure a proper supply ot air as tor example Warm air dra'wnziroin any suitable place near the motor ci@ l.machina lin the foregoing description the Wheel has heen described as rotated toy the nn'- pingement oit a )et oi air dueto the rush of yair into an evacuated casing` lThe Also, there are several factors upon which the speed of the Wheel depends. These are the strength of the vacuum applied to the case, the tightness of the case in resisting the leaking in of air, the facility with which air may enter the driving jet 18, the position of this jet 18 in reference to the Wheel 7, and the admission of air tending to run the Wheel in the opposite direction as through the jetl 20. Meansof regulating the speed of the Wheel by controlling all of these iactors are provided, any or all of which may loek used in. the instrument depending upon the facility of-the mechanical construction of the various means.. Meanstor regulating the strength of the spring 24 are shown as the screw 25 and the nut 26. Means of regulating the strength of the vacuum applied to the casing is shown in the throttlin'g valve 17. Means of regulating the tightness ot the case is illustrated in the valve la. Means of controlling the flow of air to the jet 18 is shown in the valve 19. Means ci altering the position of the jet in relation to the vvheel 7 is illustrated in the set-screw for Means for admitting air tending to run the wheel 7 in the opposite direction is shown in the jet 20 In order to facilitate the proper adjustment of the instrument so that in its neutral l position the sectors of the indicator 5 will loe oi air through the jet .might also 'he etiected loy a pressure outside the casingA instead of the vacuum heretofore described is also Within the purpose ot this invention to use a wheel operated hy other means than ln certain places Where this instrument may he used it is subjected to severe external vibrations as on an airplane. To prevent these vihrationsirom producing oscillations of the 'trame and indicating means a dashu pot is employed, comprising the piston 3@ and cylinder 31. This prevents undesirable oscillations oi the frame and indicating means Without hindering the proper Inovementto these parts in performing their normal functions. The amount of damping is regulated hy the adjustment of the valve 3i,

in the use of this instrument as a turn indicator for aircraft for maintaining a straightlight path, it is the object oi the pilot Ito so steer. his craft that neither indicator mark 5A will appear in the View openu ings on the face of the instrument. This 'temperature than that instrument, it properly observed, Will permit v the pilot to steer the machine in a perfectly straight line Without sighting from, land mariage. u

-Having thus described my invention isol rection,n1eans for regulating or stopping` the dowi air through one or the iets, indicating means operated .loy the trame.

2. An instrumentior indicating angular motion comprising, a casing having vier? openings, av frame pivoted in the casing, al

Wheel ]ournaled inthe yframe, elastic`rneans for restraining the movement o' the trame;

casing,` means for drivin and an'indieating disk connected with the frame and having distinctive marks thereon v arranged behind the view openings so that -ies operated by the frame.

lmovement of the frame exposes one of the Vmarks through a view opening.

3. An instrument for indicating angular motion,- comprising in combination: a casing,

.a frame'pivotallysupported'in said casing, 4means for elastic restraint disposed between said casing and said frame, means for damping the movement otsaid frame in'respect tosaid casing, means for varying the 1ntens'ity of said damping, a rotatable ywheel pivotally supported in said frame on an axis at right angles to the axis about which said frame is supported in said casing, means for driving said wheel, and indicatingmeans 5. An instrument for indicating angularV I motion, comprising in combination: a casf ing, means for elastic restraint disposed being, a frame pivotally supported in said castween said casing and said frame, means voperable external to the casing for varying the intensity of said elastic restraint, means' .for damping the movement of said frame in respect to said casing, means operable external to the casing for var 1ing the intensity of said damping, a rotatab e wheel pivotally supported in said frame on an axis at right ed 'by the frame.

angles tothe axis about. which said frame` issupported in said casing, means for drivlng saidwheel, and indicating means operat-- 6. Anjinstrument for indicating angular motion comprising,A a casing, a gyroscopic element in the casing, a tube connected with wit the casingrfor conveying air from a distant point to said casing, an air jet arranged to" f deliverair :t'rom thel tube lto run the' gyroscopic'element, ailvalve to vary ythe flow of the air to regulate the speed. of the gyrosco ic element,"and,indicating-means related the gyroscopic element for .showing the precession of the gyroscop'e due tothe turning of the vehicle.

' 7 An instrument for indicating angular motion, 4comprising a gyroscopicA element adapted to be driveni by air force, an indi-- catormconnected with 'and worked by the gyroscopic element, a. springtoelastically remeans t mPmg.

Aair 'y means for attaching said tubular means to strain the indicator, means for varying the tension of the spring to adjust the sensitivity of the'indication shown vby the indicatory for thev purpose of adapting the instrument to various kinds of craft such asslow or fast aircraft, anda valve for controlling the air i forcey driving rthe gyroscopic element Iand thereby adjusting the sensitivity ofc the instrument during flight so as to adapt the instrument tothe then existing flight conditions.

8. An instrument for indicating angular` motion, comprising in combination: a casing, a frame pivotally'supported in said casing, means for elastic restraint disposed between said frame and said casing, pneumatic means for damping the movement of said frame in respect to said casing, means forvarying the' intensity of said damping, a rotatable wheel pivotally supported in said .frame on an axis at right angles to tl'ie, axis about which said frame is supportedin said casing, means for'driving said wheel,

and" indicating means, operated by the frame. y A

9. An instrument for* indicating angular motion, comprising in combination: a casing, a frame pivotallyl supported in said casing, a Wheel rotatably supported'in said frame on an axis at right angles to the axis about which said frame is supported in said casing,'means for driving said Wheel, means for damping the movement of said frame in re` y spect to said casing, comprising a cylinder attached to said casing, a piston disposed in said cylinder, means connecting said piston with said frame to move said piston i`n `respect to said cylinder when'said frame moves -in \respect to said casing, a passage connecting the interior of said cylinder to the interior of said casing, a valve disposed to vary the effective size of 'saidl assage, and indicating `means operated by t e frame.

10. Aiiin'strument for indicating angular l motion, comprising in combination: la gyroscope adapted to be air driven, rotatablyl supported in a frame; said frame pivotally at. right angles to the axis .of rotation of said gyroscope; means for rotating the gyroscope comprising air directino' means coii` nected with said casing; tubulgar meansfor conve ,ing air from a'distant source to, said irecting means; readily. removable said casing, and indicating means operated by the gyroscope. 4.

11. An instrument for indicatingangular motion,`'comprising in combination: a casing, afi-ame pivotally supported in said cas: ing,` means for elastic restraint disposed between said casing and said-frame, means for varying the intensity of said elastic restraint, means 'forldamping the movement of said frame in -respect to said casing,

. `supported in a casing, the pivotal axis'being y means for varying the intensity Jof said damping, a rotatable wheel pivotallysupported in said frame .on an axis at rig i angles to the axls about which said frame 1s supported in said casing, means for rotating said Wheel, means for varying the speed of rotation of said wheel, and indicating means operable by the movement of vsaid frame in respect to said casing.

12. A turn indicator comprising, a casing, a oscope mounted therein, means to drive t e gyro'scope, an indicator operated 'by [the gyroscope, a damping means contained within the casing and cooperating with the gyroscope, and adjustment means mounted external of the casing cooperatingwith the damping meansto vary the -damping elect exerted on the gyroscope.

13. A turn indicator comprising, av casing, a gyroscope mounted therein, pneumatic means to drive the roscope, air damping erted on the gyroscope, and indicating meansv means within the casing and connecting with the ,1.3'yroscope,r and air adjustment means mounted on the outside of the casing to control the circulating of air within the damping means to vary the damping effect exoperated by the gyroscopelv e 14. An instrument for indicating angular motion comprising, a casing, a gyr'oscopic element in the casmg, a tube connected with the casing for conveying air from aY distantiriving the wheel to produce gyroe.

scopic force capable of precessing the frame,

an indicator, a connection made between the frame and indicator, a gyro centralizing spring having one end thereof attached to t e gyro frame,and. an externally exposed regulating device mounted on'tlie casing'to vwhich is attached the other end of the aforesaid centralizing-spring and by which the tension of the spring may be regulated by adjustment outside the casing.

16. Gyroscopic apparatus comprising, in combination, an air tight casing, `a gyroscopic wheel joui-nailed therein, an air tube connected with the casing to -eed air thereto from arremete source, and Ian air jet adapted to deliver air from the `tube against Athe wheel to drive same.

In testimony whereof I aix m signature.

CHARLES H. OLVIN. 

